# [luatex] The "read" half of TeX_without_TeX (in a REPL)

Eduardo Ochs eduardoochs at gmail.com
Tue Jul 17 23:55:17 CEST 2018

Hi list,

in a few days - in july 20 - I will give a talk at a TUG meeting about
the LuaTeX-based package ("dednat6") that I've been using for diagrams
since several years ago... the slides for the talk are here:

http://angg.twu.net/math-b.html#tug-2018
http://angg.twu.net/LATEX/2018tug-dednat6.pdf

The thing is: in one of the last slides I show how we can use dednat6
to run a Lua REPL in the middle of a .tex file, and how we can then
use that to inspect TeX structures - for example, we can inspect the
contents of tex.box[0] from Lua... but I am probably one of the most
un-knowleadgeable persons on that in this mailing list...

http://wiki.luatex.org/index.php/TeX_without_TeX

quite carefully, and translated its code into something that I could
run interactively by sending commands one by one to the Lua
interpreter; I had to fix several little things - the code in
TeX_without_TeX seemed to be slightly outdated - and the last time
that I tested my scripts they didn't work, they would need more fixes.

Anyone has (a link for?) an example of how to _inspect_ a TeX box from
Lua? Even a simple example, like how to show the glyphs in

\setbox0\hbox{abc}

would help me a lot...